QtTextReader.cpp

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// Copyright (c) 2008-2019 OpenShot Studios, LLC
//
// SPDX-License-Identifier: LGPL-3.0-or-later
 
#include "QtTextReader.h"
#include "CacheBase.h"
#include "Exceptions.h"
#include "Frame.h"
 
#include <QImage>
#include <QPainter>
 
using namespace openshot;

QtTextReader::QtTextReader() : width(1024), height(768), x_offset(0), y_offset(0), text(""), font(QFont("Arial", 10)), text_color("#ffffff"), background_color("#000000"), is_open(false), gravity(GRAVITY_CENTER)
{
    // Open and Close the reader, to populate it's attributes (such as height, width, etc...)
    Open();
    Close();
}
 
QtTextReader::QtTextReader(int width, int height, int x_offset, int y_offset, GravityType gravity, std::string text, QFont font, std::string text_color, std::string background_color)
: width(width), height(height), x_offset(x_offset), y_offset(y_offset), text(text), font(font), text_color(text_color), background_color(background_color), is_open(false), gravity(gravity)
{
    // Open and Close the reader, to populate it's attributes (such as height, width, etc...)
    Open();
    Close();
}
 
void QtTextReader::SetTextBackgroundColor(std::string color) {
    text_background_color = color;
 
    // Open and Close the reader, to populate it's attributes (such as height, width, etc...) plus the text background color
    Open();
    Close();
}
 
// Open reader
void QtTextReader::Open()
{
    // Open reader if not already open
    if (!is_open)
    {
        // create image
        image = std::make_shared<QImage>(width, height, QImage::Format_RGBA8888_Premultiplied);
        image->fill(QColor(background_color.c_str()));
 
        QPainter painter;
        if (!painter.begin(image.get())) {
            return;
        }
 
        // set background
        if (!text_background_color.empty()) {
            painter.setBackgroundMode(Qt::OpaqueMode);
            painter.setBackground(QBrush(text_background_color.c_str()));
        }
 
        // set font color
        painter.setPen(QPen(text_color.c_str()));
 
        // set font
        painter.setFont(font);
 
        // Set gravity (map between OpenShot and Qt)
        int align_flag = 0;
        switch (gravity)
        {
        case GRAVITY_TOP_LEFT:
            align_flag = Qt::AlignLeft | Qt::AlignTop;
            break;
        case GRAVITY_TOP:
            align_flag = Qt::AlignHCenter | Qt::AlignTop;
            break;
        case GRAVITY_TOP_RIGHT:
            align_flag = Qt::AlignRight | Qt::AlignTop;
            break;
        case GRAVITY_LEFT:
            align_flag = Qt::AlignVCenter | Qt::AlignLeft;
            break;
        case GRAVITY_CENTER:
            align_flag = Qt::AlignCenter;
            break;
        case GRAVITY_RIGHT:
            align_flag = Qt::AlignVCenter | Qt::AlignRight;
            break;
        case GRAVITY_BOTTOM_LEFT:
            align_flag = Qt::AlignLeft | Qt::AlignBottom;
            break;
        case GRAVITY_BOTTOM:
            align_flag = Qt::AlignHCenter | Qt::AlignBottom;
            break;
        case GRAVITY_BOTTOM_RIGHT:
            align_flag = Qt::AlignRight | Qt::AlignBottom;
            break;
        }
 
        // Draw image
        painter.drawText(x_offset, y_offset, width, height, align_flag, text.c_str());
 
        painter.end();
 
        // Update image properties
        info.has_audio = false;
        info.has_video = true;
        info.has_single_image = true;
        info.file_size = 0;
        info.vcodec = "QImage";
        info.width = width;
        info.height = height;
        info.pixel_ratio.num = 1;
        info.pixel_ratio.den = 1;
        info.duration = 60 * 60 * 1;  // 1 hour duration
        info.fps.num = 30;
        info.fps.den = 1;
        info.video_timebase.num = 1;
        info.video_timebase.den = 30;
        info.video_length = round(info.duration * info.fps.ToDouble());
 
        // Calculate the DAR (display aspect ratio)
        Fraction font_size(info.width * info.pixel_ratio.num, info.height * info.pixel_ratio.den);
 
        // Reduce size fraction
        font_size.Reduce();
 
        // Set the ratio based on the reduced fraction
        info.display_ratio.num = font_size.num;
        info.display_ratio.den = font_size.den;
 
        // Mark as "open"
        is_open = true;
    }
}
 
// Close reader
void QtTextReader::Close()
{
    // Close all objects, if reader is 'open'
    if (is_open)
    {
        // Mark as "closed"
        is_open = false;
 
        // Delete the image
        image.reset();
 
        info.vcodec = "";
        info.acodec = "";
    }
}
 
// Get an openshot::Frame object for a specific frame number of this reader.
std::shared_ptr<Frame> QtTextReader::GetFrame(int64_t requested_frame)
{
    // Create a scoped lock, allowing only a single thread to run the following code at one time
    const std::lock_guard<std::recursive_mutex> lock(getFrameMutex);
 
    auto sample_count = Frame::GetSamplesPerFrame(requested_frame, info.fps, info.sample_rate, info.channels);
 
    if (image)
    {
        // Create or get frame object
        auto image_frame = std::make_shared<Frame>(
            requested_frame, image->size().width(), image->size().height(),
            background_color, sample_count, info.channels);
 
        // Add Image data to frame
        image_frame->AddImage(image);
 
        // return frame object
        return image_frame;
    } else {
        // return empty frame
        auto image_frame = std::make_shared<Frame>(1, 640, 480, background_color, sample_count, info.channels);
 
        // return frame object
        return image_frame;
    }
}
 
// Generate JSON string of this object
std::string QtTextReader::Json() const {
 
    // Return formatted string
    return JsonValue().toStyledString();
}
 
// Generate Json::Value for this object
Json::Value QtTextReader::JsonValue() const {
 
    // Create root json object
    Json::Value root = ReaderBase::JsonValue(); // get parent properties
    root["type"] = "QtTextReader";
    root["width"] = width;
    root["height"] = height;
    root["x_offset"] = x_offset;
    root["y_offset"] = y_offset;
    root["text"] = text;
    root["font"] = font.toString().toStdString();
    root["text_color"] = text_color;
    root["background_color"] = background_color;
    root["text_background_color"] = text_background_color;
    root["gravity"] = gravity;
 
    // return JsonValue
    return root;
}
 
// Load JSON string into this object
void QtTextReader::SetJson(const std::string value) {
 
    // Parse JSON string into JSON objects
    try
    {
        const Json::Value root = openshot::stringToJson(value);
        // Set all values that match
        SetJsonValue(root);
    }
    catch (const std::exception& e)
    {
        // Error parsing JSON (or missing keys)
        throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
    }
}
 
// Load Json::Value into this object
void QtTextReader::SetJsonValue(const Json::Value root) {
 
    // Set parent data
    ReaderBase::SetJsonValue(root);
 
    // Set data from Json (if key is found)
    if (!root["width"].isNull())
        width = root["width"].asInt();
    if (!root["height"].isNull())
        height = root["height"].asInt();
    if (!root["x_offset"].isNull())
        x_offset = root["x_offset"].asInt();
    if (!root["y_offset"].isNull())
        y_offset = root["y_offset"].asInt();
    if (!root["text"].isNull())
        text = root["text"].asString();
    if (!root["font"].isNull())
        font.fromString(QString::fromStdString(root["font"].asString()));
    if (!root["text_color"].isNull())
        text_color = root["text_color"].asString();
    if (!root["background_color"].isNull())
        background_color = root["background_color"].asString();
    if (!root["text_background_color"].isNull())
        text_background_color = root["text_background_color"].asString();
    if (!root["gravity"].isNull())
        gravity = (GravityType) root["gravity"].asInt();
 
    // Re-Open path, and re-init everything (if needed)
    if (is_open)
    {
        Close();
        Open();
    }
}